The SRAM RED e Tap rear derailleur executes shifts the instant you demand it, with military precision. Wirelessly. It’s easy to set up, clean in appearance & delightfully uncomplicated. Mechanical necessities such as a carbon pulley cage, ceramic pulley bearings, & anodized alloy artfully blend with proprietary electronic advancements to deliver a shifting wonder. Technology AIREAUtilizing 128-bit encryption, e Tap shift signals are transmitted & received in accordance with SRAM’s proprietary wireless protocol known as AIREA. Each time an e Tap groupset is paired, a new encryption code is generated & assigned to the components in this group to ensure complete shifting security.e TAPAll of the underlying tech in our new SRAM RED e Tap groupset such as wireless shifting, advanced battery power management & mechatronics technologies are all meant to serve one ultimate purpose, to facilitate the most intuitive & consistent shifting available. This shift logic is called e Tap. Right lever makes it harder, left lever makes it easier, both levers shift the front derailleur. Simple, unmistakable, & intuitive.EXACT ACTUATIONWhen we launched our road technology from scratch we reapplied our MTB proven SRAM 1:1 actuation ratio (shifter cable travel: derailleur movement) for 10 speed rear shifting. EA helps to simplify/stabilize the uneasy act of balancing rear derailleur hanger design, tight cog spacing & exact cable tension. The result: the easiest index shifting system to set up & it stays that way. Wi F Li SRAM's Wi F Li technology accommodates a wider range of gears than a standard short-cage road derailleur. Compared to a triple chainring setup, it provides faster shifts & significant weight savings.